Maintenance machine



. June 24, 1941.

w. E. HOLT 2,246,683

MAINTENANCE MACHINE Filed Feb. 23, 1940 2 Sheets-Sheet 1 Fig. 2

BY r

j ATTORNEY.

June 24,1941. w. E. HOLT 2,246,683

MAINTENANCE MACHINE Filed Feb. 25, 1940 2 Sheets-Sheet 2 l O 17 3 m 38i6 5 /4 35 47 16 W I I, 10

z w mam- 54 w 1 1 vW/w 1N VEN TOR.

WilliamE Holt A TTORNE Y.

Patented June 24, 1941 iJNITED PATENT QFFICE MAINTENANCE MACHINE.William E. Holt, Oakland, Calif.

Application February 23, 1940, Serial No. 320,228 4', olaiias. (01. 49)

My present invention relates to theconstruc tion and operation ofmaintenance machines for treating the surfaces of floors, rugs and" thelike by scrubbing, polishing, sanding, grinding, or shampooing the same.

Such machines normally include an electric motor mounted on a basecasting, within which' is mounted a rotary brush or disc depending onthe desired operation to be performed. Machines of this type are mountedon a' pair oi supporting wheels which are adapted to be swung to aninoperative position when the machine is in actual use. M n

The main object of my invention isthe pro-1 vision of an improvedconstructionof amaintenance machine of the type described which isparticularly characterized by a silent, low cost and efficient speedreduction system between the electric motor and rotary brush of disc. Afurther and more specific objectfis the provision of a belt and pulleyspeed reduction system for a machine of the type described which affordsthe desired speed reduction while" permitting a coaxial arrangement ofthe electric motor and rotary brush and which can be readily mounted inthe base casting of themachine. A further specific object is an improvedwheel mounting and arrangement for a machine of the type described.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to andiorming apart of this specification. For a better understanding of the invention;its operatin advantages and specific objects attained by its use,reference should be had to the accompanying drawings and descriptivematter in which I have illustrated and described apreferred embodimentof my invention.

Of the drawings: I r

Fig. 1 is a side elevation of a floor maintenance machine constructed inaccordance with my in vention; v Fig. 2 is a bottom view of the body ofthe machine shown in Fig. 1; p i

Fig. 3 is an enlarged elevation, mainly in section, of the base castingand associated partsj and v Fig. 4 is an enlarged view, partly insection, similar to Fig. 2, with some of the parts removed.

In the maintenance machine illustrated; the base casting or housing H!has a plate section I I or fiat circular shape over most of its area andextended at its rear end to form a smaller curved section merging intothe front circular section.

An electric motor and housing iii are concentrically arranged relativeto and mounted on the front circular section of the base casting withthe motor shaft I4 vertically arranged and projecting downwardly throughan opening l5 in the base casting. The motor housing is secured in itsdescribed position on the base casting by screws i6.

' The smaller rear end of the base casting plate It has a recessed bossI! in which is detachably mounted a sleeve I8 for receiving the lowerend of an inclined handle pipe 19. At its upper end the pipe [9 has aswitch box 20 and a pair of handle grips 2|. At a lower point on thepipe I9 is secured a cord hook 22 which serves as a support for anelectric cable 23 adapted to connect the switch box 20 to an electricoutlet. Aconductor 24 extends down through the pipe H) from the switchbox to the motor, a thermostatically-operated cut-out switch 25 beinginterposed if'desired to prevent overheating of the motor.

' The base casting has a depending peripheral flange or skirt 26extending entirely around the plate section II and of sufiicient heightto conceal the speed reduction mechanism hereinafter described. A rubberbumper strip 21 extends around the circular part of the flange 2B and isheld inposition by a wire 28 detachably secured to the flange 26. Theportions of the flangeZGat opposite sides of the rear end of the basecasting are thickened, as shown in Fig. 4, to form short side sections30 with straight outer sides parallel to the longitudinal axis of thebase casting. The thickened side sections 39 serve to support a pair ofwheels 32, a cap screw 33 being mounted in each side section and havingan outer unthreaded portion forming an axle for the corresponding wheel.The wheels 32 are so arranged on the base casting and proportioned insuch a manner that they are above the floor level when the machine is inactual operation, but capable of forming a wheeled support when themachine is tilted back on the wheels. The direct support and describedarrangement of the wheels on the base casting eliminates any necessityfor manually shifting wheel supporting parts when the machine is put inor out of operation."

Maintenance machines of the type described have a large field of use inhospitals and other places where a minimum amount of noise is essential.The electric motor preferably used in such machines is of a lowhorsepower high speed type, such as /4-% H. P., 1475 R. P. M. The

desired brush speed is in the range 160-185 R. P. M. Reduction gearunits have been mainly used heretofore between the motor and brushshaft, but are objectionable because of their relatively high cost,inaccessability, and noisy operation.

In the machine illustrated the desired speed reduction between the motorand brush is effectively obtained by a belt and pulley system housed inthe base casting and consisting of a small pulley wheel 35 mounted onthe lower end of the motor shaft it slightly below the lever of theplate section II. The pulley 35 drives a large rear pulley 36 mounted ona vertical jack shaft 3'! through a belt 39. The jack shaft 31 isrotatably supported in a bearing 38 in the bass I! of the base casting.The shaft 31 is eccentrically mounted in the bearing 38 as indicated inFigs. 3 and 4 and the bearing can be turned in the boss ll through awing extension 38 to vary the position of the jack shaft longitudinallyof the machine and thus control the tightness of the belts 39 and 42. Asshown, the shafts l4 and 31 have their axes intersecting thelongitudinal center line of the base casting, providing a balancedarrangement. The pulley wheel 35 forms the upper part of a double pulleycarried by the shaft 31, the smaller and lower pulley thereof having adrive connection through a belt 52 with a large front pulley 43 carriedby an implement shaft 44 below and in axial alignment with the motorshaft M. The upper belt and pulleys form the first stage of speedreduction, while the lower belt and pulleys form the second stage.

The shaft 44 is mounted in a suitable bearing 45 in a flanged bearingcasing 46 supported from the plate section of the base casting by meansof set screws 4'! securing the casing 46 to a group of spaced bosses 48depending from the underside of the plate section II. The bosses 48 arearranged to avoid interference with the belt 39, as indicated in Fig. 4,and extend downwardly sufficiently to provide clearance between thebottom of the motor shaft and the top of the shaft M. The hub of thepulley 43 is extended downwardly and a brush holder 59 secured to thebottom thereof by screws The brush holder has symmetrically spacedperipheral lugs 52 which are adapted to register with correspondingslots in a plate 53 and interlock with cam surfaces on the plate to holdthe same in position. The plate 53 forms the upper part of a suitablerotary implement, such as the scrubbing brush 54 illustrated, for givinga floor or other surface the desired treatment. As shown the workingside of the brush 54 is below the level of the wheels 32, so that theWheels 32 need no adjustment to avoid contact with the floor when thebrush is in operation.

The operation of the machine will be apparent from the foregoingdescription. The machine is moved to any desired location by tilting thesame rearwardly until the supporting wheels are in contact with thefloor and the brush is free. At the desired place, the motor is switchedon and the power transmitted through the two stage belt and pulleysystem to the brush shaft 44 and brush 54. All of the rotary partsrotate in the same direction about axes symmetrically arranged relativeto the base casting. The interlocking parts of the brush and brushholder are arranged so that the direction of rotation of the brush willmaintain the same interlocked.

The machine can be readily assembled with only one reaming operation andsix drilled and tapped holes required in the base casting. The speedreduction parts are especially simple and cheap, and practicallynoiseless in operation. Repairs and renewals of these parts can bequickly made by unskilled labor due to their simple construction andaccessability.

While in accordance with the provisions of the statutes I haveillustrated and described the best form of the invention now known tome, those skilled in the art will understand that changes may be made inthe form of the apparatus disclosed without departing from the spirit ofthe invention covered by my claims, and that certain features of myinvention may sometimes be used to advantage without a corresponding useof other features.

Iclaim:

1. A floor maintenance machine comprising a horizontally arranged basehousing, an electric motor mounted on said housing with its shaftvertically arranged and extending downwardly through said housing, avertical implement shaft positioned below said motor shaft, a speedreduction system connecting said motor and implement shafts andcomprising a rotatable bearing mounted in said housing, a vertical jackshaft eccentrically journaled in said bearing, a belt and pulley driveconnection between said motor shaft and said jack shaft, a second beltand pulley drive connection between said jack shaft and said implementshaft, an implement holder mounted on said implement shaft within saidhousing, and a rotary implement detachably mounted on said holder.

2. A floor maintenance machine comprising a horizontally arrangedsymmetrically shaped base housing, an electric motor symmetricallyarranged relative to and mounted on the front portion of said housingwith its shaft vertically arranged and extending downwardly through saidhousing, a vertical implement shaft positioned below and in axialalignment with said motor shaft, a speed reduction system connectingsaid motor and implement shafts and comprising a rotatable bearingmounted in the rear portion of said housing, a vertical jack shafteccentrically journaled in said bearing, a belt and pulley driveconnection between said motor shaft and said jack shaft, a second beltand pulley drive connection between said jack shaft and said implementshaft, an implement holder mounted on said implement shaft, and a rotaryimplement detachably mounted on said holder.

3. A floor maintenance machine comprising a horizontally arranged basehousing, an electric motor mounted on the front portion of said housingwith its shaft vertically arranged and extending downwardly through saidhousing, spaced depending bosses on said housing around said motorshaft, a bearing carried by said bosses, a vertical implement shaftmounted in said bearing below and in axial alignment with said motorshaft, a speed reduction system connecting said motor and implementshafts and comprising a vertical jack shaft rotatably mounted in therear portion of said base housing, a belt and pulley drive connectionbetween said motor shaft and said jack shaft, a second belt and pulleydrive connection between said jack shaft and said implement shaft, and arotary implement mounted on said implement shaft.

4. A floor maintenance machine comprising a horizontally arranged basehousing having a symcomprising a vertical bearing mounted in the rearportion of said housing, a vertical jack shaft journaled in saidvertical bearing, a belt and pulley drive connection between said motorshaft and said jack shaft, a second belt and pulley drive connectionbetween said jack shaft and said implement shaft, an implement holderholder mounted on said implement shaft, and a r0- tary implementdetachably mounted on said 10 holder.

' WILLIAM E. HOLT.

